With the dramatic increase in the quantity and diversity of video, audio, and multimedia content that has occurred in recent years, the need for systems and techniques to efficiently deliver content to users has likewise increased. Internet-ready cell phones, personal data assistants (PDAs), and other mobile media devices have spurred increased demand for content delivery in a variety of different target formats. Furthermore, the rapid growth in user-generated content has created a large supply of media content available to users in a large number of disparate source formats.
Converting content from a source format in which the content is created or stored to a target format appropriate for use by a particular media player can be time-consuming. Delays in the delivery of media content can detract from the user's enjoyment of the content or negatively affect the user's experience in other ways. Moreover, in systems where delivery resources are limited, converting media content to a format appropriate for a particular user may result in processing bottlenecks, network congestion, and additional delays that affect other users. As a result, delays occurring during the delivery of content to individual users can lead to significant reductions in the overall efficiency of a content-delivery system.